signal extender but no connection

Hi, I purchased a TP Link wireless range extender to extend the signal from the router to another room for mobile and tablets. The range extender works good, i can see the signal is boosted to max. However, after connecting there is no internet connection despite a solid wireless connection. internet works fine, when the mobiles are next to the router, internet works fine.

I connected the extender via the WPS button from router, described in the manual.

range extender: TP-link wireless 300N range extender
router: Ubee EVW3200